Physiological effects of sleeping with the head of the bed elevated 18 in. in young healthy volunteers [with respect to orthostatic hypotension] - Source: Irish Journal of Medical Science, Oct 25, 2008

Background: Sleeping with the head of bed tilted upwards (SHU) is recommended as a treatment of orthostatic hypotension though the supporting evidence is weak. [Orthostatic hypotension involves drop in blood pressure/faintness upon rising to upright position.]

Aim: To investigate the physiological effects of sleeping with the head of bed tilted upwards amongst a group of young healthy volunteers.

Methods: Twenty-nine volunteers, mean age 22 years, underwent 1-week of sleeping with the head of bed tilted upwards at 18-in. elevation. Before and after hemodynamic and non-haemodynamic parameters were recorded.

Results: After sleeping with the head of bed tilted upwards, there were reductions in the systolic blood pressure drop on standing, upright total peripheral resistance, hemoglobin, nocturnal urinary volume, orthostatic dizziness and increases in weight, standing cardiac output and ankle circumference. There were no differences in heart rate, stroke volume, renin, aldosterone, pro-atrial natriuretic peptide or 24-h blood pressure.

Conclusions: In these healthy subjects, sleeping with the head of bed tilted upwards for 1 week had a nocturnal antidiuretic effect with both intra- and extra-vascular accumulation of fluid and was associated with reduced postural drop in systolic blood pressure and improved orthostatic tolerance.